The nationwide outbreak of enterovirus D68 (EV-D68) infections in children is continuing to fade, but another possibly related death has been reported, and the number of unexplained polio-like illnesses potentially linked to the virus has risen by 13, according to the Centers for Disease Control and Prevention (CDC).

In an update yesterday, the CDC said 39 states reported low EV-D68 activity last week, while 7 cited elevated activity, with 4 not reporting. That compares with 34 states reporting low or declining activity and 8 reporting elevated cases the week before. The number of confirmed cases, 1,105, has stayed the same since Oct 28.

The CDC said the number of deaths in patients who were infected with EV-D68 is now nine, one higher than cited a week earlier. The agency has not released any information about the cause of death in those cases, saying states are taking the lead in investigating them. Earlier this month, New Jersey health officials said EV-D68 caused the death of a 4-year-old boy.

The EV-D68 outbreak involves severe respiratory illnesses almost exclusively in children, many of whom have asthma or a history of wheezing.

More polio-like illnesses

In a separate update yesterday, the CDC said it has identified 64 recent cases of unexplained neurologic illness with limb weakness in children in 28 states, up from 51 cases in 23 states a week earlier.

The polio-like illnesses were first noticed at a Denver hospital in August, where at least 10 cases were reported. Four of those children tested positive for EV-D68.

The CDC is investigating whether the neurologic illnesses are linked to the EV-D68 outbreak, among other possible causes. Officials have not reported any conclusions yet.

In response to questions from CIDRAP News today, the agency did not reveal how many of the 64 patients with a neurologic illness fitting the case definition have tested positive for EV-D68.

It added that there are two published reports of previous neurologic illnesses in children that were confirmed as EV-D68 infection from testing of cerebrospinal fluid.

The agency said investigators are working to verify about half a dozen additional reports of unexplained neurologic illness. "In addition to the cluster in Colorado, several other smaller clusters have been identified; this remains one of the most unusual features of these cases," the statement said.